President Bush says the alleged plot to blow up U.S.-bound planes from Britain is a stark reminder for Americans that terrorists are still plotting to kill them. Opposition Democrats say the president's handling of the war in Iraq is distracting U.S. military resources from fighting those terrorists.

President Bush says U.S. and British authorities believe the arrests of more than 30 people have significantly disrupted the terrorist threat, but they cannot be sure it has been eliminated.

"This plot is further evidence that the terrorists we face are sophisticated, and constantly changing their tactics," said Mr. Bush. "On September the 11th, 2001, they used box cutters to hijack airplanes and kill thousands of innocent people. This time, we believe they planned to use liquid explosives to blow up planes in mid-air."

In his weekly radio address, the president sought to link that threat with insurgencies in Afghanistan and Iraq and Hezbollah in southern Lebanon. Mr. Bush says it is part of a broader fight against terrorists, whose ruthlessness, he says, is clear for all to see.

"The terrorists attempt to bring down airplanes full of innocent men, women, and children," he added. "They kill civilians and American servicemen in Iraq and Afghanistan, and they deliberately hide behind civilians in Lebanon. They are seeking to spread their totalitarian ideology. They're seeking to take over countries like Afghanistan and Iraq, so they can establish safe havens from which to attack free nations."

The disclosure of the alleged plot has put national security back at the center of American politics ahead of November Congressional elections.

Republicans say it shows the wisdom of keeping troops in Iraq and Afghanistan, because they are battling an enemy abroad, who would otherwise be attacking Americans at home.

Democrats say the war in Iraq is distracting resources from the fight against terrorism. In the Democratic radio address, Arkansas Senator Mark Pryor said the president has poorly managed that war, which he says is diverting more than $300 billion from the fight against terrorism.

"We need a new direction. It's time for Washington to be tough and smart about the threats we face," he said. "Americans deserve real security, not just leaders, who talk tough, but fail to deliver."

Pryor says Democrats believe the government must do more to protect Americans by boosting budgets for emergency responders and screening all cargo on aircraft and ships. He says National Guard units do not have adequate equipment, America's borders are not secure, North Korea and Iran continue to pursue nuclear weapons, and Osama bin Laden has not been found.

President Bush says it is unfortunate that some are suggesting that terrorist threats are being used for partisan political advantage. Mr. Bush says there are legitimate differences between Republicans and Democrats about the best way to fight terrorism, but there should be no disagreement about the dangers Americans face.